If you thinking about a mission to Mars, Nasa Chronology of Mars survey makes depressing reading. For every reliable Russian Mars 3 or American Viking 1, There a failed Beagle 2 (uk) quite possibly Mars Polar Lander (states). in general, Of the 42 tasks listed, Only 17 have prevailed. it can be, over the last half century, Of a Mars mission successful are around 40%.
to stay fair, Several early missions didn even make it off the launch pad and the possibilities of success have improved considerably over the decades. But you don have to return far to see failure. Only last year, Russia Phobos Grunt mission to the Martian moon Phobos failed to create it out of Earth orbit (amazingly well, It did eventually in order to burned up on re entry). perhaps the most infamous though is Nasa 1999 Mars Climate Orbiter, Where a mix up between imperial and metric styles sent the spacecraft careering into the Martian atmosphere to be destroyed.
On 6 aug (GMT) 2012 Nasa will try again with what is most likely the most ambitious and exciting Mars mission ever launched. The Mars Science lab (MSL) With the Curiosity rover ukraine wife is designed to check out whether the planet ever had the conditions to support life.
The rover is essentially a robotic geologist, That will collect and analyse soil and rock samples as it trundles on the Martian surface. and in fact is big: Around huge a Mini Cooper or small SUV; on 900kg (almost a tonne), It heavy and when hurtling the particular planet, It crossing at some 5km/s (mps), about 18,000km/h (11,000mph).
considerably, Here the manufacturing challenge: skillfully land a rapidly moving, Car sized rover on an alien soil. be sure to show your workings.
you now have the big vehicle, It actually quite challenging to slow down, Says Dan Rasky from Nasa Ames in Silicon vly, so. cal,cali.. Rasky, Now the director of the Emerging financial Space Office, Helped develop the MSL heat shield that will protect the spacecraft as it enters the Martian natural environment.
main issue with slowing down is being done with your heat shield, utters Rasky. A very tenuous atmosphere similar to 100,000 feet [30,000 metre distances] Here in the world but if you design things right, You may still slow things down enough that you can land safely. tip
Nasa engineers primarily planned to employ the same material that was used to land the Viking missions in 1975. But immediately after they tested it in a special wind tunnel, Equipped with high intensity heaters designed to simulate the conditions the MSL spacecraft will face, Things didn turn out of course.
component didn work, Rasky informs me. Very high heat just burned through the heat shield that have burned into the structure of the spacecraft. So you would have got to the outer in pieces. The engineers looked to Phenolic Impregnated Carbon Ablator, Or PICA for short. Phenolic is the identical material that we use for saucepan handles, A plastic-type materil that burns but doesn melt. PICA was first used on Nasa Stardust mission which is fitted to the SpaceX Dragon Capsule.
part of it that gets burned away. The Phenolic burns to help make a pyrolysis gas, Which actually is an important way that it absorbs the heat, Rasky details. promises to get multiple uses out of its heat shield, which you may do if you size it correctly. the warmth shield has done its job, The MSL spacecraft will likely have slowed to around 400m/s. of your rover still encased in the shell of the heat shield, The parachute deploys to slow the descent down even further. Parachutes have a proven track record on Mars of late with the Phoenix mission. though MSL, The parachute is only the first stage in a much technical landing process. This will be the first mission to use a crane looks scary but it actually eliminates a lot of the conditions that previous designs had, Says Nasa sam Sell, An engineer at the Jet Propulsion Laboratory in Pasadena who helped develop the concept.
On the eye of it, The sky crane looks ultimately complicated. Once released from its parachute and preventative shell, The lander uses motor to slow the descent. at this stage, The MSL resembles a flying bedstead with the rover slung underneath it. As this mix nears touchdown, The rover is lowered towards the surface on cables and its wheels unfurl. on-contact, The cables are severed and the skycrane (Bedstead) Flies away and fails and the rover starts work.
What may well go wrong?
silent entry
I ask Sell how they ended up with some thing so complex. You designing rover style missions notably, You quickly run into a problem where if you going to put the rover well informed about a lander, for legs and rockets, You have to get it off there somehow when you going to touch down, He exposes.
A very demanding issue of designing a way to reliably, On all kinds of different ailments on slopes, On dirt, On sand dunes drive something off the top of a stage. You also have the excess complexity that for Curiosity, This rover is over five times bigger than any previous rover built to land on Mars. Means that if they put the rover on top of the lander, There every chance it would make the whole program too top heavy, giving it to topple over. likewise, If you attached the rover underneath the lander, It could get trapped if the legs sank into sandy ground or landed at an odd angle. make sure out too.
alternative that been used successfully most notably on the recent Spirit and Opportunity missions is airbags. on this design, The rover bounces across the top encased in a cocoon. When you are looking for a stop, The airbags completely deflate, The cocoon unfolds and the rover trundles away. filter systems use that system?
You start working to make that [Airbag function] more, So it will possibly safely land a one tonne rover, You finish up with an airbag system that is very, big just doesn scale up. It was back to your chance board. Eventually, By a process of flushing out, They ended up with the sky crane.
Can think of the rover wearing a jet pack on its back, Says selling. We get 20m above the outer lining, The jet pack lowers the rover on three bridles and that whole system keeps moving down for surface with the rover held seven and a half metres below the jetpack. Landing sequence from entry into the ambiance, To the rover landing takes place readily in just seven minutes. The last command sent to MSL will be two hours before touchdown and, a result of the time delay between Earth and Mars, Mission control won know this succeeded until some 14 minutes after.
The time we get the signal that says started entry it will already have been at first glance for seven minutes! Does human body,come to be make Sell nervous? Actually makes me very hopeful. Most of us on the project have tried the design and testing of the spacecraft for years now understand how everything on the spacecraft was built and tested and put together. albeit, Is additional cautious: Always a risk that something won go well but we are certainly hoping for the top always that lingering doubt. You would like to comment on this story or anything else you have often seen on Future, go to our Facebook page or message us on Twitter.
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